The present invention relates generally to heating ventilating and air conditioning (HVAC) systems for vehicles, and more particularly to an air conditioning portion of vehicle HVAC systems.
A conventional air-conditioning system for a vehicle may include an engine driven compressor that compresses a refrigerant before it is directed into a condenser in order to remove heat from the refrigerant. The refrigerant is then directed from the condenser through an expansion device, such as a thermal expansion valve or an orifice tube, before being directed through an evaporator in the vehicle heating, ventilation and air conditioning (HVAC) module. After cooling the air flowing into the passenger cabin, the refrigerant is directed back to the compressor. The conventional air-conditioning systems also typically include an accumulator between the evaporator and compressor, or a receiver/dryer between the condenser and expansion device. Some have both an accumulator between the evaporator and compressor and a separate receiver/dryer between the condenser and expansion device. The accumulator and receiver/dryer remove moisture from the refrigerant and store extra refrigerant. The accumulator may also help to keep liquid refrigerant from entering the compressor, reducing the risk that liquid refrigerant will damage the compressor. Accordingly, the accumulator and receiver/dryer help to provide optimum operating conditions for the system.
These conventional air conditioning systems for vehicles require a significant amount of energy to operate, thus taking away from the vehicle's fuel efficiency. Consequently, more efficient air conditioning systems are desirable that still provide optimum operating conditions for the system.